The present invention relates to a fluid regulator for supplying a consumer element with fluid from a fluid reservoir and containing a valve for establishing communication between the fluid reservoir and the consumer element when the consumer element has consumed a predetermined quantity of fluid. The fluid consumer elements can, for example, be tips or nibs for writing, painting, and brush devices or also application and discharge elements of fluid dispensers.
With heretofore known writing instruments, such as fountain pens, the supply of ink to the writing tips is effected by capillaries that by means of their capillary force draw ink out of a reservoir, whereby a pressure relief opening in the reservoir is dimensioned such that only after a partial vacuum drops below a certain value is the removed ink replaced with air. In this connection, the partial vacuum in the reservoir suffices to prevent ink from running out despite its weight. These ink supply systems have the characteristic that when a temperature change of the ambient air occurs they are no longer discharge reliable, since the air in the reservoir expands and thus reduces the partial vacuum that prevents the discharge. Measures for preventing such a discharge of ink by means of additional capillary buffer storage means for the temporary accommodation of an excess volume of ink are complicated and expensive and are effective to only a limited extent.
EP 0 240 994 B1 discloses a device of the aforementioned general type, the valve of which is disposed between a fluid reservoir and an intermediate reservoir from which the consumer element is supplied with fluid via a capillary line. If the intermediate reservoir is increasingly emptied as the fluid is consumed, there results at that location a partial pressure so that the valve, one side of which borders the fluid reservoir and the other side of which borders the intermediate reservoir, opens and the intermediate reservoir is again filled with fluid. A characteristic of this system is that it can lead to permanent disruption of the fluid supply if the partial vacuum is adjusted in another manner.
It is an object of the present invention to provide a device of the aforementioned type that ensures a functionally reliable supply of a consumer element with fluid with a simple construction.